1. Technical Field
The invention is related to peer-to-peer (P2P) media streaming, and in particular, to digital rights management (DRM) schemes for use in on-demand distributed media streaming applications.
2. Related Art
According to the market research, over half of the Internet users in the United States have accessed some form of streaming media in 2004. Streaming music is still the most popular, but the popularity of streaming video is growing rapidly. Unlike web pages, a streaming media file is huge. A 3-minute movie trailer encoded at 2 megabits per second (Mbps) results in a 45 megabyte (MB) media file. Streaming media also carries stringent demands in the timing of packet delivery. The large size of the streaming media, as well as the delivery timing requirement, causes a streaming media server to be expensive to set up and run. Currently, the going wholesale rate for the network bandwidth is about $300 per Mbps per month, or $4,500 per annum for a leased T1 line (1.5 Mbps), $160,000 per annum for a leased T3 line (45 Mbps). The network bandwidth cost is a significant component of running a media server. The high bandwidth cost causes the media server today to serve mostly low bitrate, poor quality media.
The emergence of peer-to-peer (P2P) networks has revolutionized the way that media content is distributed. Popular P2P systems such as KaZaA and BitTorrent have attracted millions of users, and have efficiently distributed huge files. In such P2P networks, a peer node contributes resources, namely upload bandwidth and disk storage, in exchange for services from the other peers to improve its own content retrieval experience. Despite various hurdles, such as the presence of the leech nodes, copyright issues, virus and security concerns, P2P networks and systems flourish because users benefit from being able to retrieve content faster and more cheaply than directly retrieving the file from a server.
One challenge in a P2P network lies in the on demand streaming of media. Unlike watching TV, the user is accustomed to access the content in a non-sequential order on the Internet. The user likes the capability to fast forward or rewind the media the same way they operate their DVD or VCR player. However, many present data structures do not support this ability to randomly access streamed data in a P2P network.
Another challenge in a P2P network configuration is the issue of digital rights management (DRM). In many P2P networks, media content may be distributed without the owner's knowledge, proper authorization, and/or just compensation. This is an obstacle to the deployment of P2P content distribution systems, even though these systems may reduce the content delivery cost for the owner.
Therefore, what is needed is a system and method that enables segments of media to be read, written, accessed, and streamed in a non-sequential order. What is further needed is a DRM implementation that achieves efficient content distribution without relinquishing the control of the content.